iterator
Class NSGA2

java.lang.Object
  iterator.AbstractIterator
      iterator.AbstractOptimizer<T>
          iterator.AbstractInitialSampleBasedOptimizer<T>
              iterator.AbstractPopulationOptimizer<T>
                  iterator.BasicRealEncodedGA<MultiObjectiveProblem>
                      iterator.NSGA2

All Implemented Interfaces:

DataListener, InitialSamplesSettable, Iterable, LoggableIterator, RepeatableLoggableIterator

public class NSGA2
extends BasicRealEncodedGA<MultiObjectiveProblem>

NSGA-II algorithm. Implemented in a multithreaded fashion.

Author:

dgorur

Field Summary

Fields inherited from class iterator.BasicRealEncodedGA

comparator, extrapolationFactor, interpolationFactor, xMutation

Fields inherited from class iterator.AbstractPopulationOptimizer

currentBestG, lastBestG, nextBlock

Fields inherited from class iterator.AbstractInitialSampleBasedOptimizer

uniform

Fields inherited from class iterator.AbstractOptimizer

doubleFormat, funEvalCount, logWriter

Fields inherited from class iterator.AbstractIterator

diagnosticString, iter

Constructor Summary

NSGA2()

Method Summary

protected cern.colt.matrix.DoubleMatrix2D	computeNextPoints() Computes the next set of candidate solutions.
protected void	evaluatePoints(cern.colt.matrix.DoubleMatrix2D nextPoints) Evaluates the objective (and constraints) given set of points.
iterator.NSGA2.PopulationMember[]	getPopulation()
int	getThreadCount() Returns the number of threads this iterator can launch simultaneously.
void	init() Initialization routine
protected void	initializePopulation() Creates an initial population.
boolean	isWriteFrontsToFile() Returns true if the pareto fronts at each iteration are to be written to a file.
void	iterate() Iterates until termination.
static void	main(java.lang.String[] args)
void	setInitialSamples(cern.colt.matrix.DoubleMatrix2D initialSamples)
void	setThreadCount(int threadCount) Sets the number of threads this iterator can launch simultaneously.
void	setWriteFrontsToFile(boolean writeFrontsToFile) Sets whether the pareto fronts at each iteration will be written to file.
void	singleIteration() Performs a single iteration.
double[]	singleObjectiveSearch(int objectiveIndex, double fraction) Sorts the pareto front according to the specified objective, then returns the population member at the specified fraction of this sorted list.
iterator.NSGA2.PopulationMember[]	sortFrontOn(int objectiveIndex) Sorts the pareto front on the specified objective.
protected void	updateDiagnostics() Provides access to the diagnosticString, so that the user has flexibility over multiple methods accessing this string at different times.

Methods inherited from class iterator.BasicRealEncodedGA

getExtrapolationFactor, getInterpolationFactor, getMutationBox, getMutationFraction, getMutationProbability, makeChildren, setExtrapolationFactor, setInterpolationFactor, setMutationBox, setMutationFraction, setMutationProbability

Methods inherited from class iterator.AbstractPopulationOptimizer

getPopulationSize, setInitialSamples, setInitialSamples, setPopulationSize

Methods inherited from class iterator.AbstractInitialSampleBasedOptimizer

getRandomSeed, makeInitialSamples, setRandomSeed

Methods inherited from class iterator.AbstractOptimizer

clear, dataAdded, dataAdded, dataRemoved, dataRemoved, getDataHandler, getFunEvalCount, getLogFileName, getMaxFunEval, getProblem, isTerminated, setDataHandler, setFunEvalCount, setLogFileName, setMaxFunEval, setProblem, writeInitialRunLog

Methods inherited from class iterator.AbstractIterator

isVerbose, printDiagnostics, setVerbose

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface iterator.LoggableIterator

getLogFileName, setLogFileName

Methods inherited from interface iterator.Iterable

isTerminated

Constructor Detail

NSGA2

public NSGA2()

Method Detail

main

public static void main(java.lang.String[] args)

getPopulation

public iterator.NSGA2.PopulationMember[] getPopulation()

Overrides:

getPopulation in class BasicRealEncodedGA<MultiObjectiveProblem>

getThreadCount

public int getThreadCount()

Returns the number of threads this iterator can launch simultaneously.

Returns:

the thread count.

setThreadCount

public void setThreadCount(int threadCount)

Sets the number of threads this iterator can launch simultaneously.

Parameters:

threadCount - the given number of threads.

init

public void init()

Description copied from interface: Iterable

Initialization routine

Specified by:

init in interface Iterable

Overrides:

init in class BasicRealEncodedGA<MultiObjectiveProblem>

iterate

public void iterate()

Description copied from interface: Iterable

Iterates until termination.

Specified by:

iterate in interface Iterable

Overrides:

iterate in class AbstractOptimizer<MultiObjectiveProblem>

isWriteFrontsToFile

public boolean isWriteFrontsToFile()

Returns true if the pareto fronts at each iteration are to be written to a file.

Returns:

true if the pareto fronts are to be written to a file.

setWriteFrontsToFile

public void setWriteFrontsToFile(boolean writeFrontsToFile)

Sets whether the pareto fronts at each iteration will be written to file.

Parameters:

writeFrontsToFile - set true if fronts are to be written to file.

singleIteration

public void singleIteration()

Description copied from interface: Iterable

Performs a single iteration.

Specified by:

singleIteration in interface Iterable

Overrides:

singleIteration in class AbstractPopulationOptimizer<MultiObjectiveProblem>

singleObjectiveSearch

public double[] singleObjectiveSearch(int objectiveIndex,
                                      double fraction)

Sorts the pareto front according to the specified objective, then returns the population member at the specified fraction of this sorted list.

Parameters:

objectiveIndex - the index of the objective to sort on.

fraction - the fraction at which the population member is to be selected.

Returns:

the population member the desired fraction of the pareto front sorted along the given objective.

sortFrontOn

public iterator.NSGA2.PopulationMember[] sortFrontOn(int objectiveIndex)

Sorts the pareto front on the specified objective.

Parameters:

objectiveIndex - the index of the objective to sort on.

Returns:

an array of population members representing the pareto front sorted along the given objective.

setInitialSamples

public void setInitialSamples(cern.colt.matrix.DoubleMatrix2D initialSamples)

Specified by:

setInitialSamples in interface InitialSamplesSettable

Overrides:

setInitialSamples in class AbstractPopulationOptimizer<MultiObjectiveProblem>

Parameters:

initialSamples - initial matrix of points, stored row-wise.

initializePopulation

protected void initializePopulation()

Creates an initial population.

Overrides:

initializePopulation in class BasicRealEncodedGA<MultiObjectiveProblem>

computeNextPoints

protected cern.colt.matrix.DoubleMatrix2D computeNextPoints()

Description copied from class: AbstractPopulationOptimizer

Computes the next set of candidate solutions.

Specified by:

computeNextPoints in class AbstractPopulationOptimizer<MultiObjectiveProblem>

Returns:

a DoubleMatrix2D containing design points row-wise.

evaluatePoints

protected void evaluatePoints(cern.colt.matrix.DoubleMatrix2D nextPoints)

Description copied from class: AbstractPopulationOptimizer

Evaluates the objective (and constraints) given set of points.

Overrides:

evaluatePoints in class AbstractPopulationOptimizer<MultiObjectiveProblem>

Parameters:

nextPoints - the given set of inputs, row-wise.

updateDiagnostics

protected void updateDiagnostics()

Description copied from class: AbstractIterator

Provides access to the diagnosticString, so that the user has flexibility over multiple methods accessing this string at different times.

Overrides:

updateDiagnostics in class AbstractOptimizer<MultiObjectiveProblem>